A variety of headsets have been developed for use with telephone systems. The primary users of these headsets are attendants such as receptionists, switchboard operators and reservation clerks who spend a majority of the day speaking on the telephone. These headsets allow the wearer free use of the hands and avoid the discomfort of balancing a cumbersome handset against the ear.
The prior art headsets consist of two principle types. U.S. Pat. No. 3,548,118 issued Dec. 15, 1970 and U.S. Pat. No. 3,610,841 issued Oct. 5, 1971, both to Hutchings, disclose post-auricle or "over-the-ear" type headsets. These headsets are designed so that the receiver and microphone transducers are housed in a lightweight capsule configured with an accurately shaped surface suitable for wear behind the user's ear. U.S. Pat. No. 4,617,431 issued Oct. 14, 1986 to Scott et al. discloses a rotatable voice tube assembly for use with such headsets. U.S. Pat. No. 4,420,657 issued Dec. 13, 1983 to Larkin discloses another popular headset design. This latter design includes a wire headband for affixing the headset to the user.
Post-auricle headsets of the type described above utilize a sound tube to transmit the sonic vibrations generated by the receiver transducer to the ear of the user. The sound tube typically terminates in a vinyl ear plug. This ear plug is worn inside the auditory canal of the user's ear, sealing off the entrance of the outer ear canal.
These sound tubes suffer from several shortcomings. For example, current construction of the sound tube prevents optimum positioning of the ear plug in the user's ear because the angle of entrance to the auditory canal differs for each individual. Additionally, because the headset can be worn over either ear, the sound tube must twist to accommodate the two mirror image positions. Thus the tip tends to slip out of place unless it is positioned firmly in the ear.
Another problem inherent in the prior art ear plugs relates to possible high voltage surges. Specifically, atmospheric disturbances frequently cause high voltage surges to be introduced into the phone line. These surges are often painful to the user and can cause damage to the eardrum since the entire force of the sound is channelled directly to the ear drum via the sound tube and the ear plug which seals the ear canal.
Additionally, continual use of the snug fitting ear plug can give rise to ear infections and skin irritations. These problems have caused many users to switch to the banded, "over-the-head," headset where the cushioned earpiece rests on the outside surface of the user's ear. (See U.S. Pat. 4,420,657, cited above). Many users, however, find that the banded headset interferes with certain hair styles and would prefer the post auricle design were it not for the presently used ear plugs.